ENS 55191
ENS Event | |
|---|---|
19:07 Feb 17, 2021 | |
| Title | Invalid Actuation of Containment Isolation Valves |
| Event Description | This 60-day optional telephone notification is being made in lieu of an LER submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).
At approximately 1507 EDT on February 17, 2021, during performance of isolation logic periodic testing associated with Primary Containment Isolation System Groups 2 and 6, an invalid actuation of Group 6 Primary Containment Isolation Valves (PCIVs) (i.e., Containment Atmospheric Control/Monitoring and Post Accident Sampling isolation valves) occurred. The Group 6 isolation signal resulted from the reactor building ventilation radiation monitor `B' Channel exceeding the setpoint value. This condition likely resulted from the radiation monitor electronics being impacted by humidity levels, which exceeded the instrument design requirements that developed in the area over time as a result of the Unit 2 reactor building ventilation being secured per the test procedure. The `A' Channel, located in the same plenum, remained steady and below the setpoint value through the entire event. This, along with readings made by a Radiation Protection Technician, confirmed that there was no actual high radiation condition in the reactor building exhaust. Upon returning Unit 2 reactor building ventilation to service, the `B' Channel readings returned to be consistent with the `A' Channel. The PCIVs functioned successfully and the actuation was complete. The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation. This event did not result in any adverse impact to the health and safety of the public. The NRC Resident Inspector was notified. |
| Where | |
|---|---|
Brunswick  North Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1338.88 h55.787 days <br />7.97 weeks <br />1.834 months <br />) | |
| Opened: | Richard Barrett 13:00 Apr 14, 2021 |
| NRC Officer: | Brian Lin |
| Last Updated: | Apr 14, 2021 |
| 55191 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 569872024-01-02T04:33:0002 January 2024 04:33:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 569882023-12-28T13:15:00028 December 2023 13:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 562872022-11-09T14:06:0009 November 2022 14:06:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 561382022-08-06T10:28:0006 August 2022 10:28:00 10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification of Invalid Actuation of Containment Isolation Valves ENS 558592022-03-07T04:40:0007 March 2022 04:40:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation 60-DAY Telephone Notification ENS 557562022-01-04T18:16:0004 January 2022 18:16:00 10 CFR 50.73(a)(1), Submit an LER 60-DAY Optional Telephonic Notification for Invalid Actuation of Containment Isolation Valves ENS 551912021-02-17T19:07:00017 February 2021 19:07:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Containment Isolation Valves ENS 546752020-03-05T14:25:0005 March 2020 14:25:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Telephonic Notification of an Invalid Specified System Actuation ENS 541442019-05-10T00:00:00010 May 2019 00:00:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Notification Due to Actuation of an Emergency Diesel Generator ENS 527782017-04-06T16:12:0006 April 2017 16:12:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 520512016-05-09T10:26:0009 May 2016 10:26:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Primary Containment Isolation Valves (Pcivs) ENS 517392016-01-09T14:46:0009 January 2016 14:46:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generator ENS 515052015-09-10T01:03:00010 September 2015 01:03:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of a General Containment Isolation Signal Affecting More than One System ENS 498002013-12-11T13:18:00011 December 2013 13:18:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Primary Containment Isolation System (Pcis) Valves During I&C Maintenance ENS 491682013-05-08T01:14:0008 May 2013 01:14:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 489722013-03-04T13:04:0004 March 2013 13:04:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 442132008-03-15T20:35:00015 March 2008 20:35:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System (Pcis) Actuation ENS 437912007-09-21T18:10:00021 September 2007 18:10:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Emergency Diesel Generators ENS 416922005-05-12T08:11:00012 May 2005 08:11:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.73(a)(1), Submit an LER Technical Specification Required Shutdown Due to Loss of Emergency Bus E1 ENS 413572004-12-13T21:15:00013 December 2004 21:15:00 10 CFR 50.73(a)(1), Submit an LER Invalid System Actuation ENS 405412004-01-11T11:37:00011 January 2004 11:37:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 404962003-12-22T03:04:00022 December 2003 03:04:00 10 CFR 50.73(a)(1), Submit an LER Invalid Reactor Building Exhaust Radiation Monitor Signal Resulting in Pcis Isolations 2024-01-02T04:33:00 | |